[ElectriPat]

Hello everyone we had a call to a nursing home on Monday. Call was kitchen hood fan is no longer working. Came to the site found power going to a single 20 amp toggle switch on the wall they said controlled the fan. No ansul like I am familiar with on new Kitchens that I've done. They did have mechanical dry fire suppression. A few items under the hood like broilers, convection oven. So when I pulled the switch out I had voltage. The load was .2 a and was switching on and off. Definitely could feel cool air coming in. Basement kitchen, 2 levels of nursing home above and large hood fan with shroud sitting on 45 degree pitch roof where it was 20 up to the soffit and another 15ft up the angle. In talks about getting a picker to service the unit. I am told the fan was worked on a few years ago under different management. What would be your thoughts or assumptions? Appreciate the help as always.

 

[SWDweller]

So you never went to the roof to see the equipment?

You mention a dry fire protection system then nothing more about it. ???????

 

[MadSparky]

We really need to know more about the motor. Could be the start capacitor charging and discharging causing the reading. Might need to be replaced but we can't know until you can get boots on the roof

 

[MikeFL]

There should be 2 fans.
Exhaust fan and makeup air fan.
That's how they comply with the Balanced Air requirements of the Mechanical Code.
Both should operate at the same time from the same switch under normal conditions.

During a fire event, IIRC only the exhaust fan should operate.

Depending on how old the facility is, they may just have one fan.

 

[kb1jb1]

Blower wheel could be loose or packed with grease. Duct clogged. I came across a blower wheel that was clogged with paper towels. Put an amp meter to see if it is doing any work of moving air. But as SWD said, you need to go on the roof. Don't forget to do a job hazard analysis and wear your fall protection.

 

[hbiss]

With access to the fan as you say it is, I can guarantee you that nobody has serviced it in years. What you are feeling is a draft down the duct. That fan should be pulling air OUT.

-Hal

 

[CAUSA]

That switch is probably the control for the contact relay.

I would check for the OCP for this fan and see if single phase or 3 phase. I’m guessing 3 phase.

You will probably find the relay and other air proving switches in the suspended ceiling area or attic. By the wall that the duct leaves the buildings.

This should have a air make up system. But if it does not there might be a piece of equipment ties in to this to keep it off till the exhaust is moving.
If not this is a very very old building and the negative air in the building affects all gas burning equipment.

This would ba a good time to sell them electric heat and turf the gas boilers. 😈

 

[Awg-Dawg]

You’re going to have to go look at the fan, it could just be as simple as a belt.

 

[kb1jb1]

You’re going to have to go look at the fan, it could just be as simple as a belt.

Good comment. Usually the simplest thing is what we don't think of and the problem.

 

[hbiss]

The fan should be the first thing to check. Ok, in this case because of the degree of difficulty to get to it why not check what you can get at inside first but that shouldn't be the normal way to handle it.

-Hal

 

[Wirenuting]

Check the belt, since it’s in a crappy spot, swap it for a direct drive.

 

[hbiss]

Basement kitchen, 2 levels of nursing home above and large hood fan with shroud sitting on 45 degree pitch roof where it was 20 up to the soffit and another 15ft up the angle.

The hood, filters, ductwork and fan as well as the suppression system are supposed to be inspected/cleaned every 6 months around here. Grease laden filters, duct and fan are a big fire hazard. Since this is a nursing home, I would expect even more diligence from management. The location of that fan makes it impossible to inspect and service. In situations like that I have seen outside fire escape type stairs installed so that a tec can get to it. I have seen "Bilco" type roof hatches installed also.

If it were me, I would think about whether I should even get involved with it. Apparently, like many nursing homes, management won't spend any money until the absolutely have to. You know they aren't going to spend any money on cleaning and periodic maintenance. If there is a fire, since you were the last one to touch it, liability could fall on you, and you know the lawyers will be out for blood because it's a nursing home.

Does our insurance even cover maintenance of commercial kitchen exhaust fans?

-Hal

 

[ElectriPat]

So you never went to the roof to see the equipment?

You mention a dry fire protection system then nothing more about it. ???????

Yes need sd64 to get up that high. Dry fire suppression only, no ansul microswitch or any of the normal electrical components.

 

[ElectriPat]

There should be 2 fans.
Exhaust fan and makeup air fan.
That's how they comply with the Balanced Air requirements of the Mechanical Code.
Both should operate at the same time from the same switch under normal conditions.

During a fire event, IIRC only the exhaust fan should operate.

Depending on how old the facility is, they may just have one fan.

This as how I've always seen it as well.

 

[ElectriPat]

That switch is probably the control for the contact relay.

I would check for the OCP for this fan and see if single phase or 3 phase. I’m guessing 3 phase.

You will probably find the relay and other air proving switches in the suspended ceiling area or attic. By the wall that the duct leaves the buildings.

This should have a air make up system. But if it does not there might be a piece of equipment ties in to this to keep it off till the exhaust is moving.
If not this is a very very old building and the negative air in the building affects all gas burning equipment.

This would ba a good time to sell them electric heat and turf the gas boilers. 😈

Great suggestion need to pull panel cover. It's sheetrock ceiling with 2 floors of patients above. Could look in attic though.

 

[ElectriPat]

You’re going to have to go look at the fan, it could just be as simple as a belt.

I have never taken apart a hood fan on the roof just hooked up wires from the outside. Are they sometimes belt drive? Seems foolish but like I said I have no prior with these.

 

[ElectriPat]

The hood, filters, ductwork and fan as well as the suppression system are supposed to be inspected/cleaned every 6 months around here. Grease laden filters, duct and fan are a big fire hazard. Since this is a nursing home, I would expect even more diligence from management. The location of that fan makes it impossible to inspect and service. In situations like that I have seen outside fire escape type stairs installed so that a tec can get to it. I have seen "Bilco" type roof hatches installed also.

If it were me, I would think about whether I should even get involved with it. Apparently, like many nursing homes, management won't spend any money until the absolutely have to. You know they aren't going to spend any money on cleaning and periodic maintenance. If there is a fire, since you were the last one to touch it, liability could fall on you, and you know the lawyers will be out for blood because it's a nursing home.

Does our insurance even cover maintenance of commercial kitchen exhaust fans?

-Hal

I wouldn't say I'm particularly concerned about troubleshooting and repairing components of the electrical system at this place but you do bring up an interesting point.

 

[Wirenuting]

I have never taken apart a hood fan on the roof just hooked up wires from the outside. Are they sometimes belt drive? Seems foolish but like I said I have no prior with these.

How often does a contractor install an expensive rooftop exhaust? Not very often when they are chasing profit. That stuff is out of sight, out of mind and out of warrantee when it stops working.

 

[Wirenuting]

….

 

[glen1971]

You’re going to have to go look at the fan, it could just be as simple as a belt.

For sure! I had two fans that weren't working, and i suspected a belt on one for sure. The snow and ice finally melted enough for a ladeder, and I had time for a look. One belt was hanging on by literally a thread. Then when I went to start it, it wouldn't go. Some troubleshooting and the motor is also done (1 hp 460 volt motor). The second one sounded like crap when it ran. The belt was ok, but the bearings were toast, which isn't unexpected being an original motor of about 35 years. Further looking and I found it's manual starter was badly corroded, so I swapped it from the adjacent one, just for troubleshooting. No change, as expected, but when I looked at the alarms on the site, every time I started the second fan, there was a ground fault alarm ringing in.